This invention relates to an improvement over my invention described in U.S. Pat. No. 4,713,843 which is incorporated herein by reference.
That patent discloses a self-supporting ear protector having a flexible core member formed into a continuous loop of substantially constant thickness having the general configuration of an ear to be protected, an outer protective exposed layer secured to one side of said core member in covering relation to the central opening in the flexible member and an inner layer secured to the opposite side of the sheet of plastic material.
The flexible member is described to be formed of opposite edges abutting each other so as to form a convex configuration.
The convex configuration was an aspect that distiguished the invention in that patent from the prior art because where the prior art taught forming a convex shape, it also taught overlapping the ends of the element forming said shape which resulted in a bulky and cumbersome flexible core member.
It has been discovered that a flexible core member can be formed exhibiting the same properties of substantially constant thickness and having resilient flexible characteristics without first forming the member with a separation between the free ends thereof, with the ends then drawn to be sealed in an abutting relationship to provide the convex form.
In particular, this invention provides for an ear protector having all the improvements of those set forth in my prior patent, but which also includes forming the flexible member of a single unitary pre-cut plastic flat piece which is then heated on a mold into the desired convex shape which is retained after the plastic piece is cooled. Additionally, the flexible core member may also be formed by feeding sheets of polypropylene into a thermoforming apparatus. The sheets are heated over molds in the shape of the flexible core member having the general configuration of the ear. After the polypropylene sheet which carries the molded sections cools, the individual flexible core members are die cut. With either method, the resulting flexible member is resilient, flexible, can be snapped to fixed open and closed positions and has a substantially constant thickness.
This present core member is simpler to form, easily may be made of different plastic materials and can have its molded shape better controlled to more effectively serve to permit the ear protector to be removed and/or firmly held on the ear.